Conventionally, a tape producing apparatus for printing characters such as letters on a print tape, i.e., a long printing medium is structured to have a tape cassette, in which a cassette case of a predetermined shape houses the print tape and an ink ribbon for printing on the print tape, being mounted into a printing mechanism, and to produce a label tape by printing the characters with a thermal head on the label tape overlapped on the ink ribbon which are fed from the tape cassette.
Types of the print tape housed in the tape cassette include a transparent film tape of a predetermined width, a film tape provided with a release paper adhering to one side thereof with an adhesive, and a heat-sensitive tape having a self color development property (so-called, a thermal paper), each of which has varieties of widths. Additionally, there are ink ribbons of various colors to print on the transparent film tape. Each tape is wound on a tape spool and housed in the cassette case of the tape cassette.
The tape producing apparatus needs to receive information from the tape cassette to provide a high-quality printing and proper feeding for printing mediums of the various tape cassettes.
Japanese patent application laid-open No. 2001-88359 discloses a tape producing apparatus having tape type discrimination sensors made of a well-known mechanical switch comprising a plunger and a push-typed micro switch, and placed in a corner of a cassette storage part. A tape type of the tape cassette is detected based on an on/off signal representing the presence or absence of each sensor hole corresponding to each sensor in the cassette case of the tape cassette.
However, there has been a problem that the tape producing apparatus in the above publication cannot turn the switch on if the cassette case is not set or fixed with great precision, since an on-off stroke of the mechanical switch composed of the micro switch and others is short. There is also a risk that the switch is damaged when the cassette case is pushed into the cassette storage part of the tape printer by force.
Further, the number of sensor holes, or switches increases with increase in tape cassette variations, which raises costs. The tape producing apparatus cannot achieve commonality of the tape cassette case because there are sensor holes in the cassette case.
The tape type discrimination sensors can hardly find that the wrong tape cassette which does not meet the result of the tape type discrimination is housed in the tape cassette since the tape type in the tape cassette is detected based on an on/off signal representing the presence or absence of each sensor hole corresponding to each sensor in the cassette case of the tape cassette.